Abstract
Reliable prediction of the macromechanical properties of composite solid propellants in the microscale can accelerate the development of propellants with high mechanical properties. According to the characteristics of the composition ratio of a four-component hydroxyl-terminated polybutadiene (HTPB) propellant with the component ammonium perchlorate (AP), hydroxyl-terminated polybutadiene, aluminum powder (AL), and cyclotrimethylenetrinitramine (or RDX for short), an improved random delivery algorithm was developed to separately model filler particles with the different sizes. A step-by-step equivalent representative volume element (RVE) model was generated to reflect the microstructures of the propellant. The isotropy and uniformity of the RVE model were also tested using a two-point probability function. The Park-Paulino-Roesler (PPR) cohesive model was introduced to simulate the particle debonding (or dewetting) in solid propellant. The stress-strain curves of the propellant were obtained by the macroscopic test with the extension rate 200 mm/min at different temperatures. Based on these experimental data, the 8 characteristic parameters suitable for the microinterface of the propellant were obtained by using an inversion optimization method. A microscale finite element prediction model of the propellant considering dewetting damage was constructed to study the evolution process of the microdamage of the propellant. The predicted stress-strain curves of the propellant under different loading conditions were in good agreement with the test results.
Highlights
The development of propellant formulation is a prerequisite to significantly improve the design level of the solid rocket motor
A composite solid propellant is a kind of particle-reinforced composite material with a high filling ratio, whose macroscopic mechanical properties strongly depend on its microstructure characteristics [1, 2]
According to the characteristics of the composition ratio of a four-component hydroxyl-terminated polybutadiene (HTPB) propellant and the real debonding interface in the microstructure of the propellant, this paper proposes a stepby-step equivalent microprediction method for the mechanical properties of composite solid propellants considering dewetting damage: Based on the improved random delivery algorithm, the propellant representative volume element (RVE) model is generated using a stepwise equivalent strategy
Summary
The development of propellant formulation is a prerequisite to significantly improve the design level of the solid rocket motor. Inglis [11] combined the homogenization method with the finite element method to study the relationship between the microstructure characteristics of composite materials and the macroscopic equivalent mechanical properties. Based on the bilinear cohesion model, Zhi et al [16] analyzes the process of microscopic damage, evolution, polymerization, and macroscopic crack formation of composite solid propellants when the solid content is different, and the effect of this process on the nonlinear mechanical properties of the propellant. According to the characteristics of the composition ratio of a four-component hydroxyl-terminated polybutadiene (HTPB) propellant and the real debonding interface in the microstructure of the propellant, this paper proposes a stepby-step equivalent microprediction method for the mechanical properties of composite solid propellants considering dewetting damage: Based on the improved random delivery algorithm, the propellant representative volume element (RVE) model is generated using a stepwise equivalent strategy. A reliable prediction of the macroscopic mechanical properties of the propellant on a microscale is realized
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
